U.S. Pat. No. 4,932,367; which is hereby incorporated herein in entirety by reference; discloses a V-type four-stroke cycle internal combustion engine having an exhaust manifold and an air intake manifold disposed in the valley of the V-engine. The exhaust from the cylinders passes through exhaust passages formed in the cylinder heads which discharge exhaust into the valley of the V-engine for collection in a central exhaust cavity provided in the exhaust manifold. A single exhaust discharge outlet is in communication with the central exhaust cavity for discharging exhaust therefrom.
U.S. Pat. No. 6,622,481; which is hereby incorporated herein in entirety by reference; discloses an exhaust treatment device for an internal combustion engine of a marine propulsion system. An outer chamber contains a first inner chamber within it and slidably supports the inner chamber. An exhaust inlet conduit directs a stream of exhaust gas from a cylinder of the internal combustion engine directly into the inner chamber. The inner and outer chambers are supported relative to each other to allow relative movement of these two components in response to changes in the differential temperature between the two components. A rail system slidably supports the inner chamber relative to the outer chamber. The exhaust treatment device comprises a liquid cooled housing surrounding the inner and outer chambers. Exhaust gas is directed through the inner chamber and then into the outer chamber at a closed end of the exhaust treatment device. Exhaust gas then flow through the outer chamber to an exhaust conduit of the marine propulsion system.
U.S. Pat. No. 7,954,314; which is hereby incorporated herein in entirety by reference; discloses an engine having a cavity so that a catalyst member can be contained within the engine when an engine head portion is attached to an engine block portion. This attachment of the engine head portion and engine block portion, which forms the engine structure, captivates the catalyst member within the cavity without the need for additional brackets and housing structures. The cavity is preferably located above or at the upper regions of first and second exhaust conduits which direct exhaust upwardly from the engine head portion toward the cavity and downwardly from the cavity within the engine block portion. The first and second exhaust conduits are preferably formed as integral structures within the engine head portion and engine block portion.